Monsanto Co., the world’s largest seed company, forecast fiscal 2013 earnings will rise as much as 17 percent as sales of the newest genetically engineered corn and soybean seeds rise in the U.S. and Latin America.

Profit for the year that began Sept. 1 will rise to $4.18 to $4.32 a share, from $3.70, St. Louis-based Monsanto said today in a statement. The average of 18 estimates compiled by Bloomberg was for profit of $4.38. The shares fell 2.2 percent to $88.57 at 9:41 a.m. in New York.

Monsanto typically forecasts year-ahead earnings that are “highly achievable” and then raises the outlook as sales provide a better indication of seed volumes and prices, Don Carson, a New York-based analyst at Susquehanna Financial Group, who recommends buying the shares, said in a Sept. 30 report.

Since 2010, Monsanto Chairman and Chief Executive Officer Hugh Grant has targeted annual percentage profit increases in the “mid-teens” as the company raises prices on the newest genetically modified seeds and expands in Latin America and Eastern Europe. Monsanto stands to gain from the worst U.S. drought in more than five decades as competitors face seed shortages, the company said in June, while the U.S. Department of Agriculture forecast farmer incomes may increase.

“This outlook is the underlying base growth they think they can do, so there is upside,” such as higher prices for Roundup herbicide, Chris Shaw, a New York-based analyst at Monness Crespi Hardt & Co. who rates the shares hold, said today by phone. “Nothing in this suggests anything worrisome.”

The company also said today its net loss widened to $229 million, or 42 cents a share, in the three months through August, from $112 million, or 21 cents, a year earlier. The loss excluding a one-time benefit was 44 cents a share, wider than the 43-cent average of 18 estimates compiled by Bloomberg.

Sales in the quarter fell to $2.11 billion from $2.25 billion, trailing the $2.23 billion average estimate.

Monsanto’s fiscal fourth quarter is typically its weakest period because farmers in North America and Europe are harvesting their fields and haven’t yet begun purchasing seed and herbicide for spring planting.

Gross profit from seeds and genetic licenses will increase in fiscal 2013 by 8.1 percent to $6.55 billion, from $6.06 billion, with the growth evenly divided between the U.S. and other regions, Monsanto said. Gross profit from the unit that makes Roundup herbicide will be about $1 billion, compared with $986 million in 2012, the company said.

Sales of so-called reduced-refuge corn seed engineered to produce insecticide will rise to 36 million to 38 million acres in 2013, from 27 million acres, Monsanto said. The updated version of Roundup Ready soybeans, designed to survive herbicide applications, will be planted on 39 million to 41 million acres, compared with 32 million acres in 2012, the company said.

Monsanto may realize 12 percent higher seed prices in fiscal 2013 after the drought tightened supplies and increased seed-production costs, Carson said. Sixty percent of the company’s growth in seed revenue may come from outside the U.S., led by new engineered corn in Brazil and Argentina and conventional seed sales in Eastern Europe, he said.

Farmer incomes may rise 3.7 percent to a record $122.2 billion this year as higher grain prices and insurance payments outweigh crop losses from dry conditions, the USDA said in August.

Monsanto also will benefit from prices for glyphosate, the generic form of the company’s Roundup herbicide, that have climbed to about $13 a gallon from about $10.50 in May, Shaw, the Monness Crespi analyst, said in an Oct. 2 note.